212
Y. Liu et al.
Another possible solution to the problems is the application of an integrated
production system, i.e., farming of species with different trophic levels in one production system so that each species uses distinct niches and resources (Troell et al.
2009 ) . The waste generated by one organism can be converted into inputs (e.g.,
nutrients) for other organism(s), resulting in the optimal use of resources and
reduced environmental impacts, such as waste discharges (Troell et al. 2009 ) . For
instance, seaweed and/or mussel can be reared in the same production facility as
salmon, acting as a bio- fi lter that absorbs the dissolved wastes (e.g., nitrogen and
phosphorus) released by salmon (e.g., Buschmann et al. 1996 ; Buschmann et al.
2001 ; Chopin et al. 2001 ; Neori et al. 2004 ) . Studies indicate that the nutrients
around salmon netcages are greatly reduced, and seaweed grows much faster near
salmon netcages than at a far distance from them (e.g., Troell et al. 1997 ) . Seaweed
can also be harvested to generate extra income. Studies show that the net present
value in a salmon-mussel integrated farm is 35% higher than a salmon monoculture,
and 11% higher than the sum of salmon monoculture and mussel monoculture
(Whitmarsh et al. 2006 ) . An integrated production system is thus biologically and
economically promising, socially acceptable and risk reducing (Ridler et al. 2007 ) ,
and is gradually being adopted globally (Barrington et al. 2009 ) . Further research
on this topic needs to be conducted on a larger scale, however (Troell et al. 2003 ) .
There are some important caveats related to technological development. First,
technologies can reduce or eliminate some environmental problems, but not all of
them at once. This is mainly because such technologies take time to develop and
apply in order to get desired results. Second, the development of technologies
requires comprehensive information regarding problems and their associated
impacts, which are neither completely understood nor well studied. Finally, although
some technologies are environmentally sound and technically feasible, their application is often hampered by the need for substantial investments and a lack of organizational support.
Market-Based Instruments
Market failure is a common problem in salmon farming since the environmental
costs associated with production are often not accounted for in producers’ decisionmaking. Incorrect pricing can be remedied by incorporating the environmental costs
to re fl ect the full cost of salmon production. This can be done in the form of taxes,
tradable permits, performance bond (deposit-refund) and eco-labelling. Marketbased instruments force producers and consumers to take environmental concerns
into account.
Environmental tax is a fee levied on a producer. Ideally, it should be equal to
the environmental damages caused by the activity in question, e.g., salmon aquaculture. Environmental taxes can induce producers to reduce their pollution to a
point at which the marginal abatement cost is equal to the tax. While such a tax has
the potential to address some environmental concerns (Sylvia et al. 1996 ) , setting an
Y. Liu et al.
Another possible solution to the problems is the application of an integrated
production system, i.e., farming of species with different trophic levels in one production system so that each species uses distinct niches and resources (Troell et al.
2009 ) . The waste generated by one organism can be converted into inputs (e.g.,
nutrients) for other organism(s), resulting in the optimal use of resources and
reduced environmental impacts, such as waste discharges (Troell et al. 2009 ) . For
instance, seaweed and/or mussel can be reared in the same production facility as
salmon, acting as a bio- fi lter that absorbs the dissolved wastes (e.g., nitrogen and
phosphorus) released by salmon (e.g., Buschmann et al. 1996 ; Buschmann et al.
2001 ; Chopin et al. 2001 ; Neori et al. 2004 ) . Studies indicate that the nutrients
around salmon netcages are greatly reduced, and seaweed grows much faster near
salmon netcages than at a far distance from them (e.g., Troell et al. 1997 ) . Seaweed
can also be harvested to generate extra income. Studies show that the net present
value in a salmon-mussel integrated farm is 35% higher than a salmon monoculture,
and 11% higher than the sum of salmon monoculture and mussel monoculture
(Whitmarsh et al. 2006 ) . An integrated production system is thus biologically and
economically promising, socially acceptable and risk reducing (Ridler et al. 2007 ) ,
and is gradually being adopted globally (Barrington et al. 2009 ) . Further research
on this topic needs to be conducted on a larger scale, however (Troell et al. 2003 ) .
There are some important caveats related to technological development. First,
technologies can reduce or eliminate some environmental problems, but not all of
them at once. This is mainly because such technologies take time to develop and
apply in order to get desired results. Second, the development of technologies
requires comprehensive information regarding problems and their associated
impacts, which are neither completely understood nor well studied. Finally, although
some technologies are environmentally sound and technically feasible, their application is often hampered by the need for substantial investments and a lack of organizational support.
Market-Based Instruments
Market failure is a common problem in salmon farming since the environmental
costs associated with production are often not accounted for in producers’ decisionmaking. Incorrect pricing can be remedied by incorporating the environmental costs
to re fl ect the full cost of salmon production. This can be done in the form of taxes,
tradable permits, performance bond (deposit-refund) and eco-labelling. Marketbased instruments force producers and consumers to take environmental concerns
into account.
Environmental tax is a fee levied on a producer. Ideally, it should be equal to
the environmental damages caused by the activity in question, e.g., salmon aquaculture. Environmental taxes can induce producers to reduce their pollution to a
point at which the marginal abatement cost is equal to the tax. While such a tax has
the potential to address some environmental concerns (Sylvia et al. 1996 ) , setting an